<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS基础语法</title>
    <style>
        div {
            width: 50%;
            height: 100px;
            background-color: red;
        }
        span{
            width: auto;
            height: auto;
            background-color: aqua;
        }
    </style>
</head>

<body>
    <div>这是一个块</div>
    <div>又是一个块</div>
    <span>这是一个内联</span>
</body>

</html>